The most common and most likely answer to this crossword clue is the 7 letter word PRIESTS
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More clues leading to the result PRIESTS
Buddy explains!

The straight part
We know that "service providers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case service providers = priests.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PRIESTS mean?
PRIESTS noun- A religious clergyman (clergywoman, clergyperson) who is trained to perform services or sacrifices at a church or temple
- A blunt tool, used for quickly stunning and killing fish
- The highest office in the Aaronic priesthood
- To ordain as a priest.